1. Field of the Invention
The present invention generally relates to an electronic musical instrument capable of performing an automatic accompaniment, and more particularly to an electronic musical instrument capable of changing an accompaniment pattern or a tone color of accompaniment tone in response to a tempo.
2. Prior Art
As the conventional electronic musical instrument capable of automatically changing the accompaniment pattern, the Japanese Patent Laid-Open Publication No. 61-292692 discloses an automatic accompaniment apparatus in which a kind of accompaniment chord is detected to thereby change the accompaniment pattern. In such electronic musical instrument, the chords are divided into several chord groups such as major chords, minor chords and seventh chords, for example. As the tune progresses, the present chord must be changed. Hence, the above electronic musical instrument changes the accompaniment pattern based on which chord group the present chord belongs to.
The above electronic musical instrument can change the accompaniment pattern without manipulating switching members. However, since the accompaniment pattern must be directly determined depending on the chord progress of the tune, one accompaniment mode must be fixed at one tune. Hence, the above electronic musical instrument is disadvantageous in that a variation of performance must be limited.
On the other hand, as the conventional electronic musical instrument capable of automatically changing the tone color of the automatic accompaniment tone, the Japanese Utility Model Laid-Open No. 62-38698 discloses a first automatic accompaniment apparatus which executes a tone color control in response to a rhythm pattern of automatic accompaniment, and another Japanese Utility Model Laid-Open No. 54-8926 discloses a second automatic accompaniment apparatus which executes a tone color control in response to a touch intensity of keyboard.
However, once the rhythm is determined in the above first electronic musical instrument, the tone color must be directly determined, regardless of the image of tune. For this reason, the first automatic accompaniment apparatus is disadvantageous in that the variation of tone color must be limited. In this case, it is possible to manually change the tone color by use of a tone color selecting switch and the like. However, it is not possible to automatically change the tone color in connection with the image of tune.
In addition, a high performance technique must be required in the above second automatic accompaniment apparatus. Hence, it is disadvantageous in that it is difficult for the beginner to play the electronic musical instrument with the second automatic accompaniment apparatus.